Animal Biology Facts

The wombat is the only animal on Earth that poops in cubes - 80 to 100 neat, flat-sided blocks every night. For years nobody knew how; everyone assumed a square exit. There isn't one. Engineer Patricia Yang mapped a wombat's intestines and found two stretchy groove regions where the gut wall flexes unevenly, moulding the waste into cubes. The wombat then stacks them to mark territory - and cubes don't roll away.